Featured Research

from universities, journals, and other organizations

Unsticking The "Glue" In Blood Cells Could Save Lives

Date:

August 26, 1998

Source:

Johns Hopkins University

Summary:

It's wildfire season, and researchers hope to be in the midst of such blazes, during the month of September. Scientists funded by the National Science Foundation (NSF) and affiliated with the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, will fly a highly instrumented C-130 research aircraft around and over dangerous wildfires that may ignite this season in the United States.

Related Articles

Platelets, the blood cells that help a cut finger stop bleeding, can also take a deadly turn as they course through veins and arteries. When platelets in the bloodstream clump together as a clot, they can trigger a heart attack or a stroke. When platelets stick to a moving cancer cell, they may hide it from the body's natural defenses.

A Johns Hopkins University scientist is working on ways to disable platelets' unhealthy habits while preserving their ability to halt blood loss. The goal, says Konstantinos Konstantopoulos, is to unlock the secrets of the tacky molecules that platelets use to cling to each other and to the walls of blood vessels.

To do this, Konstantopoulos, an assistant professor of chemical engineering, has set up equipment that simulates the flow of human blood beneath a microscope. A video camera attached to the microscope lets him record and study cells that are moving as they would through blood vessels. With this equipment, he has begun testing medications that could keep platelets from using their stickiness in ways that jeopardize human health.

Under normal conditions, platelets simply circulate through the body along with red and white blood cells, posing no threat. "If you look inside the blood vessels of a healthy person, you'll see the platelets moving passively without interacting with each other or with the walls of the blood vessel," Konstantopoulos explains.

If the skin is cut, sticky molecules appear on the surface of the platelets, which rush to the site and adhere to the broken vessel wall to prevent blood loss. But sometimes, a medical disorder can set off the sticky response. If these platelets stick to each other and form a clot that stops critical blood flow to the heart or the brain, cardiac arrest or a stroke may occur. This leaves researchers with a challenge: Can platelets continue to control bleeding without forming lethal blood clots?

Fortunately, two different molecules appear to be involved in these processes. Generally, a molecule called glycoprotein Ib assists the platelets in adhering to a blood vessel wall, which is critical to controlling blood loss. But a molecule called glycoprotein IIb IIIa usually allows platelets to stick to one another. "So what the drug companies want to do," Konstantopoulos explains, "is to block the receptor for IIb IIIa, without affecting Ib. That way, you can reduce the risk of clots while continuing to limit blood loss."

In related research, the Hopkins scientist is trying to understand how platelets manage to stick to cancer cells that have broken off from a primary tumor and entered the bloodstream. "There is some evidence that these loose tumor cells can interact with platelets," Konstantopoulos says. "We think the platelets mask the cancer cells so that the body's defense mechanisms don't recognize that something foreign has invaded the bloodstream. As a result, the cancer cells are free to move anywhere, stick someplace and form another colony."

This life-threatening process is called cancer metastasis. The Hopkins researcher wants to block metastasis so that a surgeon can cut away the primary tumor without worrying that the disease will spread elsewhere. "I want to identify the molecules on the platelets and the tumor cells that allow them to stick together," he says. "Then, presumably, if you inject agents that prevent this adhesion, the body's natural defenses will recognize the cancer cell and fight it."

With these aims in mind, Konstantopoulos has obtained funding from the Whitaker Foundation to begin testing pharmacological agents that may keep platelets from sticking to each other or to cancer cells. He brings to this line of research the tools and techniques of both a chemical engineer and a biologist. Instead of simply looking at cells that remain still beneath a microscope, he studies them as they flow through tubes.

"The focus of all of this research is to learn how cells stick to other cells or to vessel walls under flow conditions," Konstantopoulos explains. "In the lab, I can simulate the conditions that occur inside the blood vessels, inside the body. In the past, biologists mainly looked at how cells interact under static conditions. We are interested in these biological processes, but we are also interested in how the flow of blood can affect these processes. We have found differences."

More From ScienceDaily

More Health & Medicine News

Featured Research

Mar. 3, 2015 — New assays can detect malaria parasites in human blood at very low levels and might be helpful in the campaign to eradicate malaria, reports a new study. An international team led by Ingrid Felger, ... full story

Mar. 3, 2015 — Adults over the age of 30 only catch flu about twice a decade, a new study suggests. So, while it may feel like more, flu-like illness can be caused by many pathogens, making it difficult to assess ... full story

Mar. 3, 2015 — No significant change in home habits of smokers have been observed in the aftermath of a ban on smoking in public spaces, researchers report. Greater inspiration to kick the habit likely comes from ... full story

Mar. 3, 2015 — Heart function has been associated with the development of dementia and Alzheimer's disease through a new study. Participants with decreased heart function, measured by cardiac index, were two to ... full story

Mar. 3, 2015 — Children of recently separated or divorced families are likelier to drink sugar-sweetened beverages than children in families where the parents are married, putting them at higher risk for obesity ... full story

Mar. 3, 2015 — Gastric bypass and similar stomach-shrinking surgeries are a popular option for obese patients looking to lose weight or treat type 2 diabetes. While the surgeries have been linked to a decreased ... full story

Mar. 3, 2015 — Most people consume more salt than they need and therefore have a higher risk of heart disease and stroke, which are the two leading causes of death worldwide. But a new study reveals that dietary ... full story

Mar. 3, 2015 — Twice as many children born to mothers who took antibiotics during pregnancy were diagnosed with asthma by age 3 than children born to mothers who didn’t take prenatal antibiotics, a new study has ... full story

Mar. 3, 2015 — Although sedatives are often administered before surgery, a randomized trial finds that among patients undergoing elective surgery under general anesthesia, receiving the sedative lorazepam before ... full story

Featured Videos

Mom Triumphs Over Tragedy, Helps Other Families

AP (Mar. 3, 2015) — After her son, Dax, died from a rare form of leukemia, Julie Locke decided to give back to the doctors at St. Jude Children&apos;s Research Hospital who tried to save his life. She raised $1.6M to help other patients and their families. (March 3)
Video provided by AP

Looted and Leaking, South Sudan's Oil Wells Pose Health Risk

AFP (Mar. 3, 2015) — Thick black puddles and a looted, leaking ruin are all that remain of the Thar Jath oil treatment facility, once a crucial part of South Sudan&apos;s mainstay industry. Duration: 01:13
Video provided by AFP

Woman Convicted of Poisoning Son

AP (Mar. 3, 2015) — A woman who blogged for years about her son&apos;s constant health woes was convicted Monday of poisoning him to death by force-feeding heavy concentrations of sodium through his stomach tube. (March 3)
Video provided by AP

Related Stories

Apr. 8, 2014 — The results of a study to determine the cumulative effects of head impacts as they relate to changes in the brain absent of concussion have been presented. The study concluded that a single season of ... full story

Jan. 29, 2014 — As the American West, parched by prolonged drought, braces for a season of potentially record-breaking wildfires, new research suggests these events not only pose an immediate threat to people's ... full story

Aug. 8, 2012 — Scientists have discovered a surprising new chemical compound in Earth's atmosphere that reacts with sulfur dioxide to form sulfuric acid, which is known to have significant impacts on climate ... full story

May 16, 2011 — Cigarette smoking, forest fires and woodburning can release a chemical that may be at least partly responsible for human health problems related to smoke exposure, according to a new study. "We ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.